feat: 成长路径支持多岗位关联 + 增强拖拽功能

前端:
- 岗位选择改为多选模式
- 增强拖拽视觉反馈（高亮、动画提示）
- 列表显示多个岗位标签

后端:
- 添加 position_ids 字段支持多岗位
- 兼容旧版 position_id 单选数据
- 返回 position_names 数组

frontend/src/views/manager/growth-path-management.vue

@@ -53,11 +53,19 @@
               </div>
             </template>
           </el-table-column>
-          <el-table-column prop="position_name" label="关联岗位" width="150">
+          <el-table-column prop="position_names" label="关联岗位" min-width="180">
             <template #default="{ row }">
-              <el-tag v-if="row.position_name" type="primary" size="small">
-                {{ row.position_name }}
-              </el-tag>
+              <template v-if="row.position_names && row.position_names.length > 0">
+                <el-tag 
+                  v-for="(name, idx) in row.position_names" 
+                  :key="idx" 
+                  type="primary" 
+                  size="small"
+                  style="margin-right: 4px; margin-bottom: 4px;"
+                >
+                  {{ name }}
+                </el-tag>
+              </template>
               <span v-else class="text-muted">未关联</span>
             </template>
           </el-table-column>
@@ -149,8 +157,11 @@
               </el-form-item>
               <el-form-item label="关联岗位">
                 <el-select 
-                  v-model="editingPath.position_id" 
-                  placeholder="选择关联岗位（可选）" 
+                  v-model="editingPath.position_ids" 
+                  placeholder="选择关联岗位（可多选）" 
+                  multiple
+                  collapse-tags
+                  collapse-tags-tooltip
                   clearable 
                   style="width: 100%"
                 >
@@ -292,7 +303,9 @@
               </div>
               <div 
                 class="selected-content"
-                @dragover.prevent
+                :class="{ 'is-dragging-over': isDraggingOver }"
+                @dragover.prevent="handleDragOver"
+                @dragleave="handleDragLeave"
                 @drop="handleDrop"
               >
                 <template v-if="editingPath.nodes && editingPath.nodes.length > 0">
@@ -421,7 +434,8 @@ interface EditingPath {
   id?: number
   name: string
   description?: string
-  position_id?: number
+  position_id?: number  // 单选（兼容旧数据）
+  position_ids: number[]  // 多选（新数据）
   stages: StageConfig[]
   estimated_duration_days?: number
   is_active: boolean
@@ -449,6 +463,8 @@ const filters = ref<{
 // 编辑状态
 const editingPath = ref<EditingPath | null>(null)
 const courseSearch = ref('')
+const isDragging = ref(false)
+const isDraggingOver = ref(false)
 
 // 基础数据
 const positions = ref<Position[]>([])
@@ -552,6 +568,7 @@ const handleCreatePath = () => {
     name: '',
     description: '',
     position_id: undefined,
+    position_ids: [],
     stages: [
       { name: '入门阶段', order: 1 },
       { name: '提升阶段', order: 2 },
@@ -570,11 +587,20 @@ const handleEditPath = async (row: GrowthPathListItem) => {
   loading.value = true
   try {
     const detail = await getGrowthPathDetail(row.id)
+    // 兼容旧数据：如果有 position_id 但没有 position_ids，则转换
+    let positionIds: number[] = []
+    if (detail.position_ids && detail.position_ids.length > 0) {
+      positionIds = detail.position_ids
+    } else if (detail.position_id) {
+      positionIds = [detail.position_id]
+    }
+    
     editingPath.value = {
       id: detail.id,
       name: detail.name,
       description: detail.description,
       position_id: detail.position_id,
+      position_ids: positionIds,
       stages: detail.stages || [
         { name: '入门阶段', order: 1 },
         { name: '提升阶段', order: 2 },
@@ -637,7 +663,9 @@ const handleSavePath = async () => {
     const payload = {
       name: editingPath.value.name,
       description: editingPath.value.description,
-      position_id: editingPath.value.position_id,
+      position_ids: editingPath.value.position_ids,
+      // 兼容旧接口：取第一个岗位作为 position_id
+      position_id: editingPath.value.position_ids.length > 0 ? editingPath.value.position_ids[0] : undefined,
       stages: editingPath.value.stages,
       estimated_duration_days: editingPath.value.estimated_duration_days,
       is_active: editingPath.value.is_active,
@@ -779,8 +807,35 @@ const handleAddCourse = (course: Course) => {
  * 拖拽开始
  */
 const handleDragStart = (event: DragEvent, course: Course) => {
+  isDragging.value = true
   event.dataTransfer!.effectAllowed = 'copy'
   event.dataTransfer!.setData('course', JSON.stringify(course))
+  // 设置拖拽图像
+  const target = event.target as HTMLElement
+  if (target) {
+    target.classList.add('is-dragging')
+  }
+}
+
+/**
+ * 拖拽进入目标区域
+ */
+const handleDragOver = (event: DragEvent) => {
+  event.preventDefault()
+  isDraggingOver.value = true
+}
+
+/**
+ * 拖拽离开目标区域
+ */
+const handleDragLeave = (event: DragEvent) => {
+  // 检查是否真的离开了（避免子元素触发）
+  const rect = (event.currentTarget as HTMLElement).getBoundingClientRect()
+  const x = event.clientX
+  const y = event.clientY
+  if (x < rect.left || x > rect.right || y < rect.top || y > rect.bottom) {
+    isDraggingOver.value = false
+  }
 }
 
 /**
@@ -788,6 +843,9 @@ const handleDragStart = (event: DragEvent, course: Course) => {
  */
 const handleDrop = (event: DragEvent) => {
   event.preventDefault()
+  isDragging.value = false
+  isDraggingOver.value = false
+  
   const courseData = event.dataTransfer!.getData('course')
   if (!courseData) return
 
@@ -1030,6 +1088,31 @@ onMounted(() => {
             flex: 1;
             overflow-y: auto;
             padding: 12px;
+            transition: all 0.3s ease;
+          }
+
+          .selected-content {
+            border: 2px dashed transparent;
+            
+            &.is-dragging-over {
+              background: #ecf5ff;
+              border-color: #667eea;
+              
+              &::before {
+                content: '松开鼠标添加课程';
+                display: block;
+                text-align: center;
+                padding: 12px;
+                color: #667eea;
+                font-weight: 500;
+                animation: pulse 1s infinite;
+              }
+            }
+          }
+          
+          @keyframes pulse {
+            0%, 100% { opacity: 1; }
+            50% { opacity: 0.6; }
           }
 
           .course-item {
@@ -1040,17 +1123,29 @@ onMounted(() => {
             margin-bottom: 8px;
             background: #f5f7fa;
             border-radius: 6px;
-            cursor: pointer;
+            cursor: grab;
             transition: all 0.2s;
+            border: 2px solid transparent;
 
             &:hover {
               background: #e6e8eb;
               transform: translateX(4px);
+              border-color: #667eea;
+            }
+
+            &:active {
+              cursor: grabbing;
+            }
+
+            &.is-dragging {
+              opacity: 0.5;
+              border-color: #667eea;
             }
 
             &.is-added {
               background: #f0f9eb;
-              border: 1px solid #67c23a;
+              border-color: #67c23a;
+              cursor: default;
             }
 
             .course-info {